1. Field of the Invention
The invention relates to a display apparatus, and more particularly, to a display apparatus in which the lengths of gate leading lines are different from each other.
2. Description of the Related Art
In an active matrix type liquid crystal display (LCD) apparatus that is used as a display apparatus, a thin film transistor (hereinafter referred to as a TFT) and a pixel electrode connected to the TFT are located adjacent to an intersection of a gate line and a source line. In addition, between the pixel electrode and an opposite electrode (common electrode) that is disposed so as to face the pixel electrode, a liquid crystal layer is formed. Moreover, by applying a voltage in accordance with the gray scale level to the pixel electrode through the TFT, which is selected by a scanning signal that is input via the gate line, an orientational state of the liquid crystal layer changes to the orientational state corresponding to the gray scale level.
In the meantime, in the above-described LCD apparatus, there is an apparatus in which a driving circuit is mounted as COG (Chip On Glass) on a prescribed region of a display panel. For example, Japanese Patent Application Laid Open JP 2006-71814 suggests a display apparatus in which among the sides of a display panel, at the side that is in parallel to the extending direction of gate lines, a projection area in which one substrate projects from the other substrate is provided, and a semiconductor device is mounted on the projection area as an IC chip that is composed of a gate driver for driving gate lines and/or a source driver for driving source lines.
However, when the gate driver is mounted on such a side of display panel that is parallel to the extending direction of the gate lines as described above, the wiring lengths of leading lines that are electrically connecting the gate lines to the gate driver are different from each other. Therefore, the time constants between the gate lines and the gate driver are different for respective gate lines. Even when the gate driver outputs a scanning signal from output terminals thereof such that on-voltages for the scan signal are the same among the gate lines, each of effective voltages of the on-voltages applied to TFTs is different with respect to each gate line. Therefore, even when a voltage corresponding to a gray scale level is being written onto each of the pixel electrodes, actual voltages that are kept in the pixel electrodes are different for different rows. For example, when a whole screen is to be displayed with the same gray level, this voltage differential results in a problem of a reduction in image quality because it causes differences in brightness on the screen.